(1) Field of the Invention
The present invention lies in the field of processing plastics materials, and more particularly the field of appliances used for locally repairing a surface made of organic polymer material. The present invention relates more specifically to appliances for locally heating a polymer material surface by confining a zone for treatment and by heating said zone for treatment by blowing a hot fluid, in particular air or steam.
The present invention provides such an appliance for localized heating of a polymer material surface to be repaired, which appliance comprises a deformable cap that forms a confinement chamber for confining the zone for treatment and means for blowing the hot fluid inside the confinement chamber.
(2) Description of Related Art
In the field of processing plastics materials, it is known to use a transportable appliance to make a localized repair to a surface made of a polymer material, in particular an organic polymer material. The appliance comprises a confinement chamber for confining a zone for treatment of the surface to be repaired, and means for blowing a hot fluid inside the chamber in order to raise the temperature of the zone for treatment. Such appliances are advantageously easily transported so as to enable them to be taken to a structure of large volume including a surface to be repaired that is treated locally over a zone of restricted extent.
More particularly, such appliances are known in which the confinement chamber is provided by a deformable cap defining an opening of the confinement chamber leading to outside the cap. The confinement chamber forms a volume that is interposed between the zone for treatment and the cap, with the outlet of the cap being for application around the zone for treatment.
By way of example, reference may be made to documents U.S. Pat. No. 4,652,319 (Hammond R. E.) and WO 2008/119114 (Ind. Composites Engineering et al.), which describe such appliances.
A general problem to be solved lies in the arrangement of the cap. A compromise needs to be found between various difficulties to be overcome and/or advantages to be obtained.
Any escape of hot fluid blown inside the confinement chamber should be avoided in order to limit energy losses while heating the zone for treatment and in order to ensure that the confinement chamber is maintained uniformly at an appropriate temperature. The surface to be repaired may be of a shape that is complex, making it difficult to install the cap in peripheral contact at its outlet along the outline of the zone for treatment. The shape of the outlet of the cap needs to be adapted to match the shape of the surface to be repaired so as to procure satisfactory confinement of the zone for treatment. The deformable nature of the outlet of the cap must make it easy to vary the shape of the confinement chamber at its outlet, with the periphery of said outlet needing to be as close as possible a fit to the shape of the outline of the zone for treatment.
For a given volume of the confinement chamber, it is appropriate for the deformable nature of the cap to enable it to be adapted easily to the shape of the outline of the zone for treatment, regardless of the shape of the surface to be repaired. It is desired to optimize the profitability of the appliance by organizing the cap in such a manner as to minimize costs while optimizing the suitability of the cap for use in repairing any surface that is to be repaired.
It is also appropriate to take advantage of the deformable nature of the cap to make the appliance easier to handle, to transport, and to stow. Installing the cap on the surface to be repaired, and removing it therefrom need to be achieved as quickly and as easily as possible.
It is advantageous for the chamber to be thermally insulated so as to avoid losing energy by transferring heat from the confinement chamber to the external surroundings. The overall shape of the cap, defining the volume of the confinement chamber, enables the confinement chamber to be ventilated uniformly. It is appropriate for the means providing thermal insulation of the confinement chamber not to impede its deformability, in particular relative to the facility of stowing and transporting the appliance easily, and more particularly its cap. The thermal insulation of the confinement chamber must be obtained efficiently while limiting the cost of obtaining the appliance.
In U.S. Pat. No. 4,652,319 and WO 2008/119114, the blower means are used to adapt the shape of the cap to the surface that is to be repaired.
For example, in U.S. Pat. No. 4,652,319, the cap comprises a rigid bell carrying a skirt arranged as a bellows at the periphery of its outlet. The skirt provides a deformable outlet for the cap that is applied against the surface to be repaired. The outlet from the cap is pressed against the surface to be repaired at the periphery of the zone for treatment, by establishing suction inside the confinement chamber. Such suction causes the cap to be deformed along its elevation axis between a resting station in which the development of the cap is optimized in elevation, and a working station in which the cap is partially compacted by compressing the bellows.
Also by way of example, according to WO 2008/119114, the cap is made up of two deformable layers that are assembled together. A first layer that is generally plane is designed to be pressed against the surface to be repaired, at the periphery of the zone for treatment. A second layer, defining the volume of the confinement chamber, is bonded to the periphery of the first layer and is shaped by blowing in the hot fluid that flows between the two layers.
Proposals are also made in document EP 2 371 523 (Aliena Aeronautica SPA) for an appliance for locally heating a polymer material surface to be repaired that is potentially complex in shape. More particularly, that document proposes confining a heating layer between the surface to be repaired and a membrane held pressed against the surface to be repaired. The membrane is pressed by establishing suction in the space between the membrane and the surface to be repaired, and by thrust exerted against the membrane by the air admitted under pressure into a chamber placed over the membrane. The chamber is defined by a concave body having an outlet that is closed by the membrane. The concave body is dome-shaped, being made of a resin wall with reinforcement embedded in the wall to hold the concave body in shape against the thrust exerted on the wall by the air admitted under pressure into the inside of the chamber cap.
The present invention provides an appliance for localized heating of a polymer material surface to be repaired, in particular a surface made of an organic polymer material. The appliance is more specifically of the type comprising a deformable cap that provides a confinement chamber for a zone for treatment of the surface to be repaired, together with blower means for blowing a hot fluid, e.g. air or steam, inside the confinement chamber.